Congrats Craig you came thru. Now you have plenty of noise all the noise you ever wanted. Get rid of the BOV.

 

I wish one of you guys lived local to me so you could come over and hear it for yourselves. The BOV setup has to be modified, Jer put it best, it's screwing up my car. Relocating the MAF is not an option. The only option we have really is to recirculate the BOV air so that it doesn't F up the air flow. But I am confident that it will cure the acceleration/air-throttle problems, and significantly quiet my setup -- which will still probably be much louder then I expected.

On a positive note, the blower sounds freaking awesome at WOT. Acceleration is screwy though, even at full throttle. Sometimes I would take off and others it would accelerate really slow.

The sad thing is, I actually had a dream about it a couple nights ago. I was driving it all around, and it was sounding/performing awesome. In my dream it actually worked right though.

Unfortunately Tom is busy until sun/mon, so my car will be sitting until then. It's been over two weeks, man I really miss driving her! It totally pWns the 4runner.

 

I just tried driving it....yeeaaaa...wasn't gonna happen.

I started her up, and it struggled to idle at first, but the blower was still moaning very loudly. The air is definately unstable and the BOV is taking that and making it a problem. Anyways. I got down the street when I decided to pop the hood and pinch the BOV line. The car sputtered even worse and ALMOST died, so I took my hand off the line. The car was still horrible to drive. My exhaust was L O U D as SIN, and smelled HORRIBLE. MY FP gauge shows normal FP but it smells like i'm running HORRIBLY rich.

My mom was in the garage talking to our neighbor when I started the car up. It is soo loud that she couldn't even hear herself think, much less try to have a convo with him.



Anyone want to make a road trip down to FLA?

 

I'm sure you'll get this all worked out Craig. After all you're pioneering this and some R&D time is to be expected.

 

what is Tom saying about all this?

 

He knows about all the issues and can't fix the BOV issue 'till sunday/monday.

The shaft ran to the blower is completely straight and connected to the engine, so I don't see how it would overwork the bearings, since the shaft would have to be bent for the bearings to be overworked. The blower was dissected and cleaned out, with new GM oil put in, so it essentially in perfect working order. The screwed up air/fuel ratio and driveability will hopefully be 100% attributed to the BOV. Amazing how something soo small can make such a huge difference in sound/driveability/performance.

 

craig, relocating the maf is,imo, the solution. To get the right solution, you first have to locate the problem, right. The BOV sounds like a secondary problem to me. If you closed it, opened it, pinched the line, and opened the line and it still runs like ****, then that really does not sound like the problem. Stephen has hit the nail on the head if you asked me. I know If I were you I'd like for it to be the easy fix(BOV) but I doubt that's it bro. Your boy Tom has some troubleshooting to do. Does he not guarantee his work. He did design the setup did he not. I do understand your frustration. I still don't have any oil pressure on my new turbo motor that I just put in my SE-R. It'll work out bud, just be patient

 

i think the setup will work with the MAF on the blower inlet side and a bypass valve in place between the blower and TB but its very aparent that the MAF is making your motor run like crap its just that the blower is so close to the MAF that the air hasnt calmed down yet. with a vortec or turbo theres about 10x longer piping before the maf, i bet the same would happen if the turbo setup didnt incorperate an IC

isnt it posible for you to unplug the MAF and start the car and see if it idles normal i know you can do this on a 3rd gen but not sure about 4th good luck

 

Good luck Craig, **** looks intense!

 

It is hard to tell just by looking at these pictures on the MAF's distance from the blower. What is the distance between them? Anyway, to prevent swirl flow via the compressor from throwing off the MAF readings, the MAF should be located at least 14 inches from the blower. Good luck.

 

Wow Craig, looks great! I didn't think you'd have it done this soon

You may want to crunch some fuel pressure & injector numbers so you know how much fuel w/boost you're getting. An 8:1 disk and 6-7psi seems like a tad overkill on the fuel to me. Swapping the 6:1 may be easier for tuning, and a little less rich until you get it on the dyno. Just an idea on the astoundingly high FP w/low boost.

--note: I *MIGHT* be wrong here, as I'm using supercharger knowledge. You turbo guys run the 6:1 disk on 6-7psi, or did you need to switch to the 8? Someone with better fuel system knowledge correct/confirm me please

Hope you get everything running nicely soon Craig!

 

Jay25 should reply to this post...

 

6-7psi you should be fine with a 6:1 disc.

 

It's about 6 inches in between the blower and MAF. The piping comes out of the bottom of the blower, and right into the MAF. Sooo.....

 

Guys, the main problem here is the noise. It's not supposed to sound this way. Obviously recirculating the BOV air will fix it, but I don't know to how much degree. The MAF sits about 6-7" away from the blower, and the BOV about 4-5" away from the blower, right in the middle of the two. So I don't know if bypassing that air would solve the problem or not...

Basically there are two things really wrong. The ungodly and unhealthy noise, and the horrible idle/driving. My neighbor from across the street thought I had a bad throwout bearing when I drove past him, only with the sound magnified.

 

Hey, you wanted noisy

Just kidding. I'm trying to think what solutions there are to having less noise. You may want to ask some of the guys at the v6 accord forums (I don't know the address). Their comptech supercharger kit was the first thing I thought of when I saw your setup.



Looks a lot alike!

See if you can track someone who owns one of those and ask them about the configuration with MAF / BOV / "quieting" issues.

 

Yeah me too, it does look alot like the AV6 kit installed on their engine. I think any high-end performance shop could fix it to be the way you want it (or close at least), but it would cost alot.

 

The question is where is the TB located on the AV6 setup? If its before the blower it would eliminate all of Craigs problems. Once you put the TB before the blower you eliminate the need for a BOV all together.

 

AV6 does not have a MAF sensor... they use a MAP sensor instead.

 

I don't think the MAF is Craigs problem...its all about where the TB is located in relation to the blower. A roots blower really wants the TB to be BEFORE the blower...and Craig's setup doesn't have that...which is why he needs a BOV, which sounds like it is causing his problems.

 

Yep. You listening, Craig?

 

i dont see why a roots setup would be any different that the vortec setup except the fact that the vortec blower outlet has about 5ft more piping to the maf. does the roots push more air at idle than the vortec

 

The roots makes almost full boost right off idle, whereas the Vortech doesn't even start making boost until 3600rpm. (stock pulley)

I don't think theres enough room to relocate my throttle body?? Could I keep my MAF in the same spot? Sounds like a lot of work. I guess simply bypassing the BOV's air won't help cure my noise/drivability problems?

 

Yep. Any ideas on how I might go about doing this?

 

You and Tom will have to get creative. You need to extend throttle cables, sensor wires, coolant hoses, etc. Doesn't sound like fun.

It would be ugly and corny as sin, but perhaps get a second TB so your stock one can remain where it is? Dunno if that would work, but it may save headaches of extending everything but the throttle cable.

I'd get as much info as you can on how AV6's do it. If they've got their TB after the blower, than there's a solution out there.

I think you could keep your MAF in the same spot, because its proven that it can handle the 10psi that it would/could see.

 

Recirculate the BOV and then build a pressure tester to find other leaks, U can find more info on the pressure tester here.

 

I think I have the answer!!!


The reason the vortech blower can go before the TB is because the vortech is a pressure pump, a blower is a PD (volume) pump, and works differentely. Alot diferentely! It may be trying to force too much air into your car at idle, based on how fast the blower is turning.
Let me explain.
This is whats hapening:
Lets assume that when the throttle is closed that you are essentially pumping air into a dead headed tube. If we look at the compressor map for any centrifugal pump (like the vortech): as flow decreases pressure increases to a certain point and then stops when flow = zero, at low rpms the zero flow pressure will be very low (close to zero). Thus the vortech blower can safely push against the closed TB and not build a ton of pressure.


Now lets consider the eaton blower (Still assuming the throttle plate is closed and AFTER the blower). The way a PD blower works is by essentially grabbing a certain volume of air (between the lobes of the blower cams) To an extent, we can say that for each revolution of the blower we grab the same amount of air and push it out the other side. This is because the air that its grabbing from is always at atmospheric pressure, so each time the chamber that moves the air through the blower opens, the same amount goes into the chamber, and the same amount is forced out into the intake pipe. Now, whats happening, is that even at idle you are continuously jamming air into the intake pipe, which has no where to go, except SCREAMING out of the BOV. Also, since the air cannot escape out the BOV fast enough you are building alot of pressure between the blower and the TB. When you open the TB all this air RUSHES into the intake manifold and makes your car think that a ridiculous amount of air is flowing into the engine (which is true). This is whats making it surge like crazy between shifts. To verify this, move your pressure gauge to before the TB to read the pressure at the MAF side of the TB.

Now, If the TB is before the roots blower, here is what happens. lets imagine that there is a little air trapped between the closed throttle plate and the blower entry. As the blower moves the air from the entry to the exit, it basically runs out of air to move because none can get passed the trottle plate (basically, there the blower a vaccum on the inlet side of itself). With this setup, the MAF side intake pipe will only build a tiny bit of pressure. because it doesnt have any air to move.

THE SOLUTION IS TO MOVE THE TB TO BEFORE TH BLOWER!!!!!!!!

 

I have to agree with on-alert. It looks like the TB is getting boost even at idle and it's screwing up everthing. ie.. pressurizing the AAICV. That would explain why the bov is moving at idle also. Looks like you need to maybe run a bypass valve from maybe the bov to somewhere downstream of the maf so the ecu doesn't double measure the air.

 

Thanks for the link. I couldn't tell from the pictures where the TB was located, but that makes it clear.

I think on_alert's explination is dead on. It explains Craig's problems quite well.

...I surprised a guy named "Turbo Tom" didn't know this...

 

I think of it this way: The Eaton blower is making almost full boost off idle. So, in comparison with my old V1 setup, it would be like me revving to ~5800rpm and just holding it there. The amount of air being pushed through the BOV and the sheer loudness of it is what I have now CONSTANTLY at idle. All that air means bad air readings and a weezy, surging idle, cruising, and shifting. Also makes for an EXTREMELY loud system. My supercharger weezes like a dying animal do to the rocky idle, and the BOV's massive air flow weezes too. Sounds horrible, haha.

I think at first we are going to try and bypass the BOV air and see if that works, hopefully it will be the cure to the problem and not just a little helper.

 

I am his first Supercharger setup. All his other work consists purely of turbocharging.

 

Craig, if on_alert's explaination is not defining your problem AND solution, then I give up. I just spoke with my brother who has a mechanical engineering degree from Rose Hulman, and he said that on_alert is DEAD ON the target. He's pretty d@mn experienced with this stuff. I'd go with his post an run with it buddy.

 

Craig, I realize that sounds easier, but I don't think it will get you anywhere. As has been mentioned many times, the correct way to solve your problems is to get rid of the BOV and move the TB to before the blower.

 

This is Brian, Cullen's brother.

Ejj is right. Removing the Blow off valve will quiet the noise somewhat, but It will only cause the build up of more pressure in the piping and cause the idle and erratic acceleration problems to worsen. As long as the pressure is there all problems will persist. Does not the driveability of the car concern you rather than the noise it's making.
Brian J.

 

I'd try a bypass valve and tubing before any major changes are made. But that's just me I guess.

 

Being that the throttle body is placed after the blower you would need a by-pass or recirculation valve that could handle a large volume of air consistently.
Brian

 

Well, being that we would be custom making the valve, don't you think we could make one strong enough to handle all that pressure? But in your previous post, you said doing this will only WORSEN my problems...?

 

It would really only need to handle xx psi from idle to maybe just off idle. Because once you open the throttle place, you won't be pressurizing the AAICV anymore and the car no longer would be idling anyway. Controling it would be the question. A vaccum operated valve might not work as the engine is apparently seeing positive pressure all the time.

 

It's not really about stength as much as handling a large volume of air consistently, being that the blower is producing a large amount of pressure even at low rpm. Removing the BOV completely WOULD worsen the problems because there would be no release for the pressure, but a recirculation valve would give a release and feed back into the system. I believe this would be a half measure solution to your problem though. Just trying to be helpful
Brian

 

Good point. Cullen just explained to me the placement of the idle air control valve. I'm trying to do a layout in my mind of the system by looking at your pictures and given jeff's info i believe the bypass valve would not work either.
Brian